English

Suppression of one-dimensional weak localization by band asymmetry

Disordered Systems and Neural Networks 2023-08-25 v2 Quantum Physics

Abstract

We investigate disorder-induced localization in metals that break time-reversal and inversion symmetries through their energy dispersion, ϵkϵk\epsilon_{k}\neq\epsilon_{-k}, but lack Berry phases. In the perturbative regime of disorder, we show that weak localization is suppressed due to a mismatch of the Fermi velocities of left and right movers. To substantiate this analytical result, we perform quench numerics on chains shorter than the Anderson localization length -- the latter computed and verified to be finite using the recursive Green's function method -- and find a sharp rise in the saturation value of the participation ratio due to band asymmetry, indicating a tendency to delocalize. Interestingly, for weak disorder strength η\eta, we see a better fit to the scaling behavior ξ1/η2\xi\propto1/\eta^{2} for asymmetric bands than conventional symmetric ones.

Keywords

Cite

@article{arxiv.2302.13816,
  title  = {Suppression of one-dimensional weak localization by band asymmetry},
  author = {Kartikeya Arora and Rajeev Singh and Pavan Hosur},
  journal= {arXiv preprint arXiv:2302.13816},
  year   = {2023}
}

Comments

Added scaling of localization length with weak disorder